Small wheels in the Himalayas

It's three days until I drag a bike box out of the front door, past the banana trees and the bright red lipstick palms, past the cockatoos squawking in the paperbark trees, past the large buddha statue hiding in the tropical undergrowth, and place the box onto the roof of my 4WD.
Five weeks away from Marie and my daughters with the promise to check-in everyday on my satellite phone when I'm alone in the Himalayas riding a bicycle.
I've been waking at two in the morning with feelings of trepidation and excitement mixed with doubt. Can I ride above above 5,000 metres? Am I prepared?
Four days later I'll be in Leh, Ladakh (meaning land of high passes) waiting for my body to acclimatise.
My companion is a green Moulton TSR bicycle with a Sturmey Archer 3 speed hub and nine speed cassette.